Official Text and Analysis.

Requires cities and counties to adopt ordinances and development and zoning regulations that authorize creating accessory dwelling units within designated urban growth areas.

Clarifies that any action taken by counties and cities to comply with this act within urban growth area (UGA) boundaries are not subject to legal challenge brought, on or after January 1, 2018, under the GMA or SEPA. (2) Modifies the requirement that local ordinances and development regulations must allow for ADUs on all lots that contain a single-family housing unit, duplex, or triplex to single-family housing lots only with the allowance restricted to either an attached ADU or detached ADU, and subjects this requirement to any local regulations and limitations as determined by the local legislative authority. (3) Clarifies that ADUs may not be considered as contributing to the underlying density with the UGA boundary of a county for GMA compliance purposes. (4) Removes language addressing new or separate utility connections and basing connection fees and capacity charges on the size and number of plumbing fixtures for ADUs. (5) Requires local ADU regulations to not be inconsistent with water availability requirements, water system plans, or established policies adopted by cities or counties. (6) Removes the restriction on the prohibition on the sale or conveyance of a condo unit based on the grounds it was originally an ADU. (7) Requires ADUs to be accessible to fire department apparatus by way of public street or approved fire apparatus access. (8) Modifies the off-street parking prohibition to ADUs within .5 miles of a transit stop for fixed rail or for regular bus service. (9) Encourages local regulations to minimize their impact on ADU construction costs. (10) Encourages, instead of mandates, local regulations not to establish setback regulations for ADUs more restrictive than single- family housing unit regulations. (11) Removes the prohibition on establishing tree retention requirements for ADUs in addition to those for single-family units. (12) Authorizes local regulations to exempt designated historical districts. (13) Requires cities and counties to review impact fees to ensure that impact fees on ADUs are commensurate with actual impact of the ADU and are less than impact fees on single-family housing units. (14) Removes the requirement that cities and counties adopt ordinances and regulations regarding minimum gross floor area consistent with the act. (15) Clarifies that cities of at least 2,500 and less than 10,000 and of which any portion lies within the boundaries of a regional transit authority or a transit agency are subject to the requirements of the act.

Specifies that cities and counties may not establish a transportation impact fee for accessory dwelling units within .5 miles of a transit stop for fixed rail or regular bus service that is greater than 50 percent of the amount set for single-family residences.

Exempts cities that have current accessory dwelling unit regulations in place as of the effective date of this act, from the new accessory dwelling unit regulation requirements, but encourages such cities to adopt similar policies before its next comprehensive review is due under the GMA. (2) Requires local ordinances and regulations to allow on lots of 2500 sq. ft. or less at least one attached accessory dwelling unit with the option to allow at least one detached accessory dwelling unit on such lots. (3) Provides local jurisdictions the ability to enact regulations related to accessory dwelling units being used as a short-term rental.